One of the opportunities to modernize the critical path in drug development is to employ the concept of ‘model-based drug development’. This presentation outlines six key components of model-based drug development, including: 1) PK/PD and disease modeling, 2) exposure-response meta-analyses of competitor data, 3) design and trial execution models, 4) data-analytic models, 5) quantitative decision criteria, and 6) trial performance metrics. Clinical trial simulation techniques are employed to integrate information from these six components to aid clinical trial design evaluation and drug development decision-making. An example is shown to illustrate this model-based framework for quantitative decision-making. The presentation concludes with a discussion regarding the challenges to the successful implementation of model-based drug development.